1. Field of the Invention
The embodiments of the present invention relate to integrated circuit (IC) device packaging technology, and in particular, to ball grid array (BGA) packages having improved thermal and/or electrical characteristics.
2. Related Art
The die-up plastic ball grid array package was first introduced by Motorola and was called Overmolded Plastic Pad Array Carriers (OMPAC). For further detail on this package type, refer to “Overmolded Plastic Pad Array Carriers (OMPAC): A Low Cost, High Interconnect Density IC Packaging Solution for Consumer and Industrial Electronics,” Electronic Components and Technology Conference, IEEE, pp. 176-182, 1991, which is incorporated by reference herein in its entirety. Commonly known as a “PBGA” package, the plastic ball grid array (PBGA) package features a plastic circuit board (substrate) typically made of Bismaleimide Triazine (BT) resins or FR4 materials.
FIG. 1 shows a conventional PBGA package 100. As shown in FIG. 1, PBGA package 100 has the following features:
a) An integrated circuit (IC) semiconductor die 118 is attached directly to the top surface of a printed circuit substrate 102.
b) Wirebonds 104 are used to electrically connect bond pads 112 of IC die 118 to a printed circuit on substrate 102.
c) A matrix of solder balls 110 is attached to the bottom surface of substrate 102.
d) A plastic molding compound 108 encapsulates both IC die 118 and wirebonds 104, and covers a portion of the top surface of substrate 102, for environmental protection. A periphery of the surface of substrate 102 around molding compound 108 is exposed (not covered by molding compound 108).
e) A die attach material 106 attaches IC die 118 to substrate 102.
Conventional BGA packages, such as shown in FIG. 1, have drawbacks, including: (1) a high package profile; (2) poor thermal performance; and (3) a long electrical interconnection path between the IC die and external pins of the package, and other drawbacks. Thus, what is needed are BGA packages with improved thermal performance, improved electrical performance, reduced package assembly yield loss, and improved package reliability.